1. Field of the Technology
The present technology relates to a solar battery and a fabrication method thereof, particularly to a solar battery having an aluminum electrode formed on at least a portion of the back side of a solar cell, and a method of fabricating such a solar battery.
2. Description of the Background Art
An aluminum electrode and the like are formed at a major area of the back side of a solar cell, identified as the back electrode of a solar battery. Formation of such an aluminum electrode is effected by applying, drying, and then baking aluminum paste on at least a portion of the back side of the solar cell. In the baking process of aluminum paste to form an aluminum electrode, the surface of the aluminum electrode was warped in a concave manner by shrinkage caused by the baking of aluminum paste, which was attributed to the cracking and defect of the solar battery in the subsequent processing step thereof.
There is an approach to reduce this warping of a solar battery by reducing the applied amount of aluminum paste (refer to Japanese Patent Laying-Open No. 2000-090734). However, this approach had the disadvantage that sufficient electrical characteristics cannot be achieved by the reduction of the BSF (Back Surface Field) effect corresponding to the smaller amount of aluminum paste applied. Although the aforementioned publication discloses evaluation of the composition of the aluminum paste itself to suppress reduction in the BSF effect, it is difficult to avoid reduction in the BSF effect. There are also the problems of a rise in cost due to the added agent, deterioration of the appearance of the baked surface, and the like.
It is desired to reduce warping of a solar battery without degrading the electrical characteristics, reliability, and appearance.